Crucial 256GB Solid State Drive for $180Crucial M4 256GB SATA3 SSD for $200, and code 24HRSALE606D applies $20 off in the cart ($0.70/GB).
Its 2.5" size fits inside most laptop computers (replacing an existing hard drive), or can be installed inside a desktop computer with a 2.5-to-3.5-inch bracket.
For a cheaper option, a Mushkin Enhanced Chronos 120GB SSD deal is still available at $90 ($0.75/GB).